Automatic scraper control for rotogravure-printing presses



c. G. PRITCHARD.

AUTOMATIC SCRAPER CONTROL FOR ROTOGRAVURE PRINTING PRESSES. APPLICATION FILED NOV. 26,1920.

1,383,338. l Patented July 5, 1921.

j? Nia UNITED STATES ori-fic.

CARL G. PRITCHARD, F WARREN, OHIO, ASSIGNORv TO THE HARRIS AUTOMATIC PRESS COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO,

AUTOMATIC SCRAPER CONTROL FOR ROTOGRAVURE-PRINTING PRESSES.

Specification of Letters Patent.

Patented July 5, 1921-.

Original application iiled May 29, 1917, Serial No. 171,613.4 Divided and this application led November 26, 1920. Serial No.` 426,382.

To all whom t may concern Be it known that I, CARL G. PRI'rcHAno, a citizen of the United States, and a resident of Varren, in the county of, Trumbull and State of Ohio, have invented certain new and useful Improvements in Automatic. Scraper Controls for Rotogravure-Printing Presses, of which the following is a specification, reference being made to the accompanying drawings, forming a -part thereof.

My invention relates to rotogravure or intaglio printing-presses, and the invention is embodied in improved mechanism for automatically controlling the scraper knife used to remove the surplus ink from the etched plate von the form cylinder simultaneously with the stoppage of the printing operation by disconnecting the press as a whole from the driving source of power. My present application for patent is a division of my pending application, Serial Number 171,613, filed May 29, 1917.

In printing-presses o-f this type the printing operation is performed by a copper plate or shell suitably secured to the vform cylinder, the outer surface of which is etched or engraved, such etched or engraved portions being adapted to contain the ink, while the smooth portions of the plate are free from ink. The ink is fed to the form cylinder in relatively large quantities from the ink fountain, and a sharp scraper knife is arranged tangentially tothe circular etched plate and used to remove all surplus ink from the outer-most surfaces of the plate. The edge of the knife is also arranged parallel to the axis of rotation of the form cylinder and the surplus ink falls back into the fountain as the cylinder is rotated. In presses of this type, it is necessary to employ devices to lift the scraper knife from the surface of the copper plate upon the stoppage of the printing operation, lest the sharp edge of the knife cut into and ruin the etched surface of the copper plate by any reverse movement of the press, thereby rendering the plate useless for further printing.

The objects of my invention are, among other things, to provide a simple and effective automatic scraper control mechanism, which may be actuated simultaneously with the stoppage of the press, controlled either by the operator or automatically byA a sheet detector device and tripping mechanism which operate upon the failure of the feed Fig. 3 is an end view partly in cross-sec-l tion, of the tripping mechanism shownin Figs. 1 and 2.

Similar numerals refer to similar parts throughout the several figures.

Ihave embodied my improvements in a construction in which the scraper throw-off 1s connected to one of the clutch members secured to the driving shaft, so that the scraper knife is thrown oif the plate cylinder with the disconnecting ofthe power clutch upon the stoppage of the press. When the clutch members are reset upon the starting of the press, the edge of the scraper knife is restored to contact with plate cylinder, or

the knife may be placedm operative position on the cylinder before the press is Y started.

Referring toFigs. 1 and 2, 4 designates the frame of the press in which the form cylinder 5 carrying the etched plate 6, and the impression cylinder 7 are mounted on the shafts 8 and 9 respectively journaled in the frame 4, the two cylinders 5 and 7 forming a printing couple. The two cylinders -are geared together by suitable gears whose pitch-diameter coincides with the periphery of the respective cylinders to secure proper rotation for the'cylinders. Power is transmitted to the impression cylinder 7, from the loose and fixed pulleys 10 and 11 to the driving shaft 12 journaled in the frame 4 as shown. 13 is the positive clutch member slidably secured to the shaft 12 and is adapt'- ed to engage the clutch member 14 mounted onthe shaft 15; the clutch 14 carries the miter-gear 16 which engages with the mitergear 17 mounted on the impression cylinder shaft 9 to secure the counter-clock-wise rotation of the impression cylinder 7. 18 is a stub-shaft secured to the frame 4 and 19 is a sleeve journaled on the shaft 18 which sleeve 19 has a depending arm 20 carryin at its lower end the clutch yoke 21 adapte to engage, and coact with, the annular groove 22 formed in the clutch member 13 as shown in Fig. 1. Extending upwardly from the sleeve 19 is the arm 23 having the rod 24 pivotally secured to its outer end. The rod 24 extends forwardly of the press and near its outer end carries the lug 25 on its under side adapted to engage and coact with the pin 26 secured to the outer end of the arm 27 mounted on the transverse shaft 28 journale'd in the frame 4. rIhe shaft 28 carries the hub 29 upon which the scraper knife 30 is removably secured by set screws (not shown). 31 is the ink fountain from which ink is supplied to the plate 6 through the rotatable ink roller 32.` The shaft 28 car- -ries the arm 33 from which the gravity weights 34 are suspended to normally maintain the edge of the knife in contact with the plate 6. When the rod 24 Vis moved to the left either by the lifting of the handlever 35 or by the action of the automatic sheet-detector device hereafter to be described, the knife 30 will be directly thrown off from the plate 6 simultaneously with the disconnecting of the clutch members 13 and 14 which stops the press. two throw-offs will be controlled and actuated by the automatic sheet-detector device, shown more particularly in Fig. 3.

In Figs. 1, 2 and 3, 36 indicates the feedtable, and in Fig. 3,37 designates the sheet of stock that is being fed to the press. Extending transversely above the feed-table 36 and journaled to projections in the frame 4 is the rock-shaft 38 which carries, the arm 39 connected bythe rod 40 which is pivoted to the pin 41 set in the impression cylinder shaft 9, so as to impart to the shaft 38 an oscillating movement during the operation of the press. 42, 42 designates two grooved collars rigidly secured to the shaft 38, and

adjacent eachgrooved collar 42 is the disk 43 of substantially the same diameter as the collars 42, which disk 43 is secured to the inner end ofthe tubular shaft 44, which is loosely sleeved on, and incloses a portion of the shaft 38, as shown in Fig. 3. The shaft 44 has rigidly secured to its outer end the collar 45 upon which is mounted the arm 46 which, in turn, is connected to the hand-lever 35 by the link 47. 48 designates the'triplever pivoted at 49 between the parallel sides of the grooved collars 42 so that its longer' and heavier arm is held from falling into the opening 50 cut in the top of the feed-table 36 by the interposition ofthe stock 37 as shown in Figs. 1 and 3. At the opposite end the trip-lever 48 is T-shaped to form the tooth 51, and in the peripheries of the sides of the collars 42, and also in the periphery of the disk 43 are 4formed cut-outs 52 and 53 respectively. Ordinarily the tooth -51 rests Preferably the i.,sss,sele

against,.or is in proximity to, the periphery of the disk 43; it can engage with the cut-out 52 of 'the collars 42 only when it can fall into the cut-out 53 of the disk 43. lfVhen this occurs the disk 43 with its shaft 44, which are normally at rest, are locked to and turn with the oscillating shaft 38. rlhe entrance of this toothl 51 into locking engagement with the disk 43 will occur upon the failure or interruption in the feed supply. When the stock 37is in properl position, as shown in Figs. 1 and 3, the curved longer `arm of the triplever 48 will engage therewith and will be supported thereby, so as to be lprevented from lowering into the opening 50, and from turning sufficiently to interlock with the disk 43. If the stock 37 should, at any time, be interrupted or absent, the longer arm of the trip-lever 48 will fall of its own weight into the opening 50, thereby causing the tooth 51 to interlock with the cut-out 53 in the disk 43. Thus the tubular shaft 44 will be caused to oscillate with the shaft 38 so as to cause the arm' 46 to lift the hand-lever 35 through the link 47 to simultaneously disconnect the clutch members 13 and 14 on the one hand, and to directly throw the scraperknife 30 off the surface of the plate 6 0nthe other. Any other form of sheetdetector device may be utilized in my machine to accomplish the same purpose and re-v sult. When the clutch is reset the knife 30 is automatically brought at once into contact with the plate 6 as soon as the press starts, or the knife may be returned to the cylinder before starting'by raising the rod 24 out of engagement with the pin 26.

The foregoing construction embodies the principles of my invention as applied to a two-cylinder press2 but it is obvious that my invention is applicable to other forms of printing-presses, and that other combinations and modes ofoperation may be made, the foregoing being sufficient to disclose the underlying principles and advantages involved.

I claim as my invention:

1. In a printing-press having printing and impression members, inkin' devices for said printing member, means or removing surplus ink from said printing member, means for driving 'said members, clutch means for connecting ordisconnecting said driving means in relation to said members, and means actuated by said clutch means for changing the relation of said ink removing means to said printing member.

2. In a printing-press having printing and impression members, inking devices for said printing member, means for removing j surplus ink from said printing member, means for driving said members, clutch means,

controlled by the stock, for connecting or disconnecting said' drivin means in relation to said members, an

means actuated I means in inoperative position.

rintinv member. A b

3. In a printingpress having printing and impression members, inking devices for -said printing member, means for removing surplus ink Jfrom said printing member, means for driving said members comprising a 'pair' of shiftable clutchv members, and means for simultaneouslydisconnecting said clutch members and placing said ink-re-y moving means in inoperative position. 4. In a printing-press having, printing and impression members, inln devices for said printing member, means or removing surplus ink from` said printing member, means for driving said members comprising a pair of'shiftable clutch members, and automatic means for simultaneously disconnecting said clutch members and placing said ink-removing means in inoperative position. i

5. In a printing-press having printing and impression members, inking vdevices for said/printing member, means for removing surplus ink from said printing member, means for driving said members comprising a pair of shiftable clutch members, and automatic means, controlled bythe stock, for simultaneously di'sconnectng said clutch members and placing said ink-removing 6. In a printing-press having printing and impression members, inking devices for said 4printing member, means -for re'mbving surplus ink from said printing member, means for driving said members comprisin Ia pair of shii'table `clutch members, an

manually operable means for simultaneously disconnecting said clutch members and plac-v ing said ink-removing means in inoperative i position.

7'. In a printing-press having printing and impression members, inkin devices for said printing member, means or removing surplus ink from said printing member, means for driving said members, clutch means for connecting or disconnecting said driving means inrelation Vto Isaid members, and means actuated -by 1said clutch means for changing the relationy of said ink removing means to said printing member, said last means allowing the ink-removing means tobe moved into operative position before the clutch means are connected.

8. In a printing-press Having printing and impression mem ers, inkinA devices fora said printing member, means or removing surplus ink from said printing' member, means for driving said members, clutch means, controlled bythe stock, for connecting or disconnecting said driving means in relation to said members, and means actuated by said clutch means for changing the relation lof said ink removing means to said printing member, said last means alloW- ing the ink-removin means to be moved vinto operative position before the clutch means are connected.

9. In a printing-press having printing and impression members, inking devices .for said printing member, means for removing surplus ink from said printing member, means for driving said 'members comprising a v pair of shiftable clutch members, and means for simultaneously disconnecting said clutch members and placing said ink-removing means in inoperative position, said last means allowing the ink-removing means to be moved into operative position before the clutch membersI are connected.

10. In a printing-press having printing and impression members, inking devices for said printing member, means for removing surplus ink from said printing imember, means for driving said members comprising a pair of shiftable clutch members, and automatic means for simultaneously disconnecting said clutch members and placing said ink-removing means in inoperative position, said last means allowing the ink-removingmeans to be'movedY into operative position before the clutch members are connected.

11. In a printing-press having printing and impression members, inkin devices for said printing member, means or removing surplus ink from said printing member,

means for driving said members comprising a pair of shiftable 'clutch members, and au-v tomatic means, controlled Vby the stock, forl simultaneously disconnecting said clutch members yand placing s aid ink-removing means -in `inoperative position, said ,last

means allowing the'ink-removing means'to..

tive position before the clutch members are connected.

CARL G. riiirciiaan. .r 

